Try to mimic a tad closer to an actual AppleTV.

Sometimes AirPlay photo isn't seen on my mac... so just in case...
Minor code clean-up. C++-ify it
Fix typo introduced in earlier commit

would have prevented airplay to work on new system
Change theme widget names to be a bit more universal

Was too focused on playing music, a legacy from originally using the miniplayer theme
Add MythNotification convenience constructors
Add support for all types of notifications via the UDP listener interface.
Add support for all type of notifications via mythutils
Full screen notification theme tweaks